Threading mechanism for automatic lathes.



1.1. HOGAN, J. F. JUDD & L. M. WA TE.

THREADING MECHANISM FOR AUTOMATIC LITHES.

APPLICATION HLEU MAY I9, 1915.

1,222,954. Patented Apr. 17. 1917.

3 SHEETSSHET I.

J06 Judd ba Wane gr-mrn r/Ewe: $55922! 1.1. HOGAN, J. F. mun '& L. M.WAITE.

THREADING MECHANISM FOR AUTOMATIC LITHES.

Patented Apr. 17, I917.

APPLICATION FILED MAY I9. NIB.

3 SHEET,8SHEET 2.

.II III RN mmN J. 1. HOGAN, J. F JUDD &'L. M. WAITE.

THREADING MECHANISM FOR AUTOMATIC LAIHE'S.

APPLICATION FILED MAYIQ, ms. 1,222,954. Patented Apr. 17,1917.

2 SHEETS-SHEET a UNITED STATES PATEFT OFFICE.

JAMES J. HOGAN, JOHN F. J UDD, ANI) LYMAN M. WAITE, HF, FITCHBURG,MASSACHU- SETTS, ASSIGNORS TO FITCHBUBG IVIAGH'INE WORKS, 0F FITGHBURG,MASSACHU- SETTS, A. CORPORATION OF MASSACHUSETTS.

'I'HBEADING, MECHANISM FOR AUTOMATIG LATHES.

SpecificationofLetters Patent.

Patented Apr. 1'7, 1917.

Application filed May 19, 1916. Serial No. as .659,

To all whom it may concern:

Be it known that we, JAMEs J. I'IOGAN, JOHN F. JUDD, and LYMAN M. Warm,citizens of the United States, all residing at Fitchburg, in the countyof Worcester and State of Massachusetts, have invented a new and usefulThreading Mechanism for Automatic Lathes, of which the following is aspecification.

This invention relates to a threading mechanism for automatic lathes ofthe type in which the threadingdie is continuously revolved in. the samedirection as the stock, but at a speed less or greater than that of thestock according as the die is cutting or running 011 of the stock.

While many features of our invention are capable of general application,we have herein shown the invention'as applied to a multiplespindleautomatic lathe of the general type shown in the patent to Grant, No.926,735, issued July 6, 1909. In this type of lathe the workiis bothrotated and advanced longitudinally toward the tools which are mountedin a fixed tool head.

It is the general object of our invention to provide an improvedthreading mechanism particularly adapted to this type of lathe, in whichthe mechanical construction is simplified and the operation is made morereliable.

Withthis general object in view, one fea ture of our invention relatesto a construction by the use of which the threading mechanism may occupyeither one of two successive positions in the lathe, or if desired twothreading mechanisms may be used at thesame time, one in each of twosuccessive positions. A second feature of our invention relates to theprovision of a support on whichis mounted the mechanism which-com trolsthe threading die, this support and the mechanism thereon being readilyremov able and replaceable as a unit. Other features of our inventionrelate to the provision of an improvedlsystem of controlling devices forthe threading mechanism by which the necessary adjustments canbe easilymadeand to an improved and simplified clutch mechanism forcontrolling-the speed changes of the die.

()ur invention also relates to certain ar' rangements and combinationsof parts which will be hereinafter described and more particularlypointed out in the appended claims.

i drive;

.A preferred form of our invention is shown in the drawings in whichFigure 1 is a side elevation of a portion of a lathe, with our improvedthreading mechanism attached thereto;

Fig. 2 is. a top plan view of the -mecha nism shown in Fig. l; i

Fig. 3 is a leit-hand end elevation, partly in section taken along theline 33 in Fig. 1

Fig. i is a front elevation of thedie spindie and associated parts,partly in section. and taken along the line 4.4 in Fig. 2;

Fig. 5 is a fr ontelevation of the detachable support fo:- the diecontrolling mechanism, and the parts carried thereby;

.Fig. 6 is a detail elevation. of the compound lever thrr ugh which thespeed changes of the threading die are controlled, taken along the line6--6 inFig. l; a l

Fig. 7 is a front elevation ofthe compound lever sho WninFig. 6;

Figg8 isa se( tional view taken along the line 88 in Fig. 4e, andshowing the clutch mechanism for ihe low speed drive;

Fig. 9 .is a partial sectional view similar to Fig. 8, but showing theparts in a different position;

Fig. 10 is a sectionalview taken along the line 10-10 in Fig. 4, andshowing the clutch mechanism for the high speed Fig. 11 is a partialsectional view similar to Fig. 10, but showing the parts in a dif ferentposition, and

-Fig..12 is a detail sectional view along the line 1212 in Fig. 4.

Referring to ihe drawings we have indicated at 10-10 two of therotatable spindles which support consecutive pieces of work W. These'spindlesflare inoun-tedin a head 11 slidable on ways 12 formed on thebed 13 of th a machine. The movement of the head is controlled throughconnections, not shown. from a main cam shaft 14; rotatable in suitablehearings in the bed 13. The usual'box tools are mounted in a rigid toolhead 15, ant. the threading die 16 is secured to-qa spindle 17 (Fig. 4)rotatable and s'lidab'le in i he toolhead 15.

At the left of the tool head 15 there is provided an additional fixedframe member 18 having guide ways 19 and 20 (Fig. 3) formed on the frontface thereof. A support 21 (Figs. 3 and 5) is provided with-a dovetailedgroore by means of which the support may be accurately positioned uponeither guide way to correspond to the third or fourth positions of thework holding spin-' dles.

As shown in the drawings the support is mounted on the upper guide wayor in the third position, but it may be readily removed therefrom andmaybe replaced in the fourth position upon the guide way 20. Furthermoreit is sometimes desirable to perform two successive threading operationsin an automatic lathe, and for such purposes a separate support 21 withits attached mechanism may be mounted upon each of the guide ways 19 and20, thus permitting the threading operations to be performed in both thethird and fourth positions.

The mechanism mounted upon the support 21 is used for advancing andwithdrawing the die relatively to the work, and also for controlling thespeed changes of the die. For the purpose of positionmg the die axiallyarack sleeve 22 (Fig. 5) is slidably but nonrotatably mounted in abearing 21 on the support 21. An intermediate shaft 23 is rotatable in abearing 21 -on the support 21 and-a rod 230 fixed in said shaft extendsfreely through the sleeve 22 and is retained therein by a collar 231. V

A swivel connection is thus formed between the shaft 23 and the sleeve22. The shaft 23 extends into a recess 170 (Fig. 4) formed in the end ofthe spindle 17 and is retained therein by a cross pin 232 which extendsthrough slots 233 in the spindle 17. A spring 234 in the recess 170holds the pin normally against the outer ends of the slots but permitsthe parts to yield when the threading die engages the work.

The rack teeth upon the sleeve 22 are positioned to engage a spur gear24 mounted on a short shaft 25, rotatable in bearings in the support 21.A pinion 26 is secured to the outer end of the shaft 25 and meshes witha segment gear 27 pivoted upon a stud 28 secured to the support 21. Thesupport 21 is fixed upon the frame member 18 by a number of bolts orstuds 29 (Fig. 2).

A roll 30 (Figs. 2 and 5) is mounted in an arm 31 which is adjustableabout the axis of the stud 28, and which ma be fixed to the segment gear27 by means 0 a bolt32 extending through a segmental slot 33 formed inthe gear. The roll 30 is positioned for engagement by a pawl or dog 34(Fig. 2) pivoted in a block35, keyed to a sliding bar 36, andlongitudinally adjustable thereon.

The bar 36 carries a series of pawls or dogs for controlling theoperations'of the threading die when in the upper or third position, anda corresponding bar 37 is provided forsupporting the dogs which controlthe threading mechanism when in the fourth position. The bars'36 and 37are slidable at their right-hand ends in bearings 38-38 6 (Fig. 1)formed on the side of the tool head 15. The bars also extend through across bar 39 to which each bar is rigidly secured. A third bar 40 issecured at one end to the center of the cross bar 39 and is slidable ina bearing 41 carried by the frame member 18. The bars 36 and 37 are thussupported for longitudinal reciprocation parallel to the axis of thethreading die and the work holding spindles.

he cross bar 39 is connected by a link 42 to the upper end of an arm 43keyed to a horizontal shaft 44 which is mounted in fixed hearings in theframe 13. A second arm 45 is secured to the shaft 44 between the sidesof the frame and is provided with a cam roll 46 positioned to engage anirregular cam 47 mounted upon the main or cam shaft 14. This shaft 14makes one complete revolution for each advance of the workholdingspindles, and the sliding bars 36 and 37 are therefore given one fullreciproca tion after each advance of the spindles to new positions.

As the bar 36 is moved to the right after the work W is positioned infront of the threading die 16, the pawl or dog 34 engages the roll 30and partially rotates the segment gear 27, thereby advancing the racksleeve 22, the shaft 23, the spindle 17 and the die 16. By the continuedmovement of the segment gear 27 the roll 30 is carried downward untilthe dog 34 passes freely over the roll.

T he parts are so timed that the advancing stock W will engage the diesubstantially at the moment when the roll 30 passes below the dog 34. Atthis instant the dog, being directly above the roll, is effective toprevent backward movement of the die, thus holding the die against thethrust of the work until the die begins to feed forward in its cuttingmovement, when the shaft 23 and sleeve 22 will be drawn forward by thedie independently of the dog 34.

We will now describe the mechanism for rotating the die at suitablespeeds to secure the cutting of the thread and the withdrawal of thedie. A sleeve 50 (Fig. 4) is loosely mounted upon the intermediate shaft23, but is prevented from free rotation thereon by a loose key ortumbler 51 (Fig. 8) whichclosely limits the relative an ular movement ofthe sleeve and shaft. he tumbler 51 is held within the sleeve 50 by acap 50 (Fig. 4) which is extended to find a bearing in the head 15.

A high speed gear 52 normally rotates freely upon the outside of thesleeve 50, and a low speed gear 53 is also mounted for rotationconcentric with the shaft 23 and sleeve 50. The gears 52 and 53 areconstantly driven by gears 54 and 55 (Fig. 2) suitably connected withthe driving mechanism of the machine, the proportions of the gears beingtain the driving engagement such that the gear 52 willrotate at a speedgreater than that of the work, while the gear 53 rotates at a speed lessthan that of the Work.

The operationof these gears during thread cutting is such that the gear53 acts as a brake or retarding device to hold the die back so that thework will be turned into the die' during. the cutting operation, whilethe gear 52 drives the die ahead of the work, so that the die will berun off after the thread has been cut.

Under normal conditions the shaft 23 and the threading die arecontinuously rotated at slow speed by the gear 53. This gear is providedupon its inner surface with a series of ratchet teeth 56 (Fig. 8)positioned for engagement with a pawl 57 slidable outwardly in a recessin the sleeve 50. A light flat spring 58 forces the pawl yieldinglyoutwardly to engage. the ratchet teeth 56 and this spring is ofsuflicient stren th to mainlhetween the gear 53 and. the shaft-23 whenno thread is being out; c

"As soon. as the die engages the stock it tends to rotate at the samespeed as the stock, and therefore to run ahead of the gear 53 and thesleeve which is latched theretobythe pawl 57. Under these conditions theshaft 23 presses against the lower end of the tumbler 51 (as viewed inFig. 8).

I I The tumbler, however, engages the sleeve 50 35 only at a point nearthe center of the tumbler, and the'pressure of the shaft 23 thereforeacts throughthe tumbler 51 as a lever to'apositively holdthe pawl 57 inengagel'nent with the ratchet teeth 56. So long, as

the die is cutting, therefore, the gear 53 retards therotation of thedie, and the pull of the. stock transmitted through the shaft23 andthetui'nbler .51 holds the pawl 57 in operative engagement withthe teeth56.

After the thread has been cut to the de sired length it is necessary toconnect the high speed gear tothe shaft 23 in order thatthe diemay berun off of the work.

' The gear-52 is provided with oppositely disposed ratchet teeth 60(Fig. 10) and a slid. ing pawl 61is mounted in a recessin the sleeve 50.collar 62 (Fig. 4) is slidable uponthe shaft 23, said collar beingformed. 0; When the pawl 61 entwo diameters. gages the smallerdiameter,as shown in 4: and 10, thehigh speed gear, is inoperativel. ,Wlien thecollar is moved to the right so that its portion of larger diameter Thesleeve '62 is slidably secured to the shaft 23 by a keypin 64; (Fig. 12)which engages a key way or slot 65 formed in the shaft At its left-handend the sleeve 62 is provided with a flmge 62 fitting loosely within apocket in a two part sleeve 66 slidable in a bearing fOIX'I'lGClOll thesupport 21. A stud67 (Fig. 3) carried by the sleeve 66 extends through aslot in the side of the bearing into position for engagement by acompound operating lever.

The compound levar comprises a member 70 (Fig. 7) pivoted at 71 to thesupport 21, and having a slotted engagement at its lower endwith thestud 67 At its upper end the member 70 is provided with a stud 72 whichextends through a slot 73 in the second member 74 of the compound lever.The member 74 is made in two parts for purpose of adjustment and ispivoted at 75 to the support 21. This member has an en gaging portion74A which extendsdownwardly into the pati of a dog 76 pivoted in a block77, and adjustably secured to the sliding bar 36. i

\Ve have previously described the manner in which the die is. advancedby the dog 34 until it engages the stock. It is then drawn forward uponthe st ock during the cutting operation, and at the same time the stockis advancing toward the left as viewed in the drawings. The dog 7 6 willbe so adjusted that it will. engagethe portion 74 of the compound leverwhen substantially the desired'length of thread has been cut. Suchengagement througlc the stud 67 and the sleeve 66 will slide the sleeve62 to the right along the shaft 23, thus forcing outward the pawl 61 andor using driving engagement of the high speed gear 52. The die will thenbe rotated faster than thework WV with the result that it will bequickly run off of the work.

During this portion of the o gieration the sleeve 50 will. drive theshaft 23 instead of retarding the same, and thetumbler 51 will be moved.to the position shown in Fig. 9, thus releasing the pawl 57 which willthereafter snap lightly over the ratchet teeth 56,

being forced outward only by the light the work, a third dog 80 (Fig.pivoted in g a; block 8]. adjustable on the bar 36 engages a shoulder 27a (Fig. 5) of the segn'ient gear 27 and partially rotates the gear in adirection opposite to that caused bythe en{. 'agement of the pawl 34withthe roll 30. The sleeve 22v and shaft 23, and the spindle l7 arethuspositively returned to their origi nal inoperative posit ions.

As the shaft 23 approaches its extreme. 'left-l'iandf positiont 1e keypin 64 (Figs. t and 12) reaches the end of the ,slot 65, and isthereafter moved a short distance to the left .ca-rryingwith it thesleeve 62, and'releasing the pawl 61, thereby disengaging the high speedg'eatr 52, and restoring the spindle 23 to the control of the low speedgear 53.

It will be noted that the entire operation thus far described has takenplace during the continued movement of the bar 36 to the right. Afterthese operations have been completed the bar 36 makes an idle stroke tothe left in returning to initial position. The dogs 34, 76 and 80 areeach yieldingly mounted in their supportin blocks so that they areinoperative on their return stroke. Suitable springs are provided forrestoring the dogs to their operative positions before the beginning ofthe next movement to the right.

It is often necessary to cut a thread up to a shoulder whichnecessitates the stoppin of the die at a fixed point in its trave. Forsuch operation We provide an auxiliary device for shifting the sleeves66 and 62 through which the high speed gear is controlled. Thisauxiliary device comprises one or more pins 90 (Fig. 4) slidable inholes in the bearing 21 and positioned to engage the end of the sleeve66. The opposite ends of the pins extend beyond the bearing intoposition for engagement by a collar 91 which may be clamped to the shaft23 in any desired position. When the collar engages the pins 90 themotion of the shaft 23 will be transmitted directly to the sleeves 66and 62, and the high speed pawl 61 will thus be forced positivelyoutward at a fixed point in the travel of the shaft 23 and the die 16.

While this arrangement is more positive in its action than the compoundleve'r pre-' viously described, the latter device is used whereverpossible, as the compounding of the levers causes the sleeve 66 to movemore rapidly than the shaft 23, and thus throws the pawl into operativeposition with less opportunity for Wear of the parts before drivingengagement is established.

A collar 95 loosely encircles the sleeves 66 and 62 and holds the gear52 in position upon the sleeve 50.

Whenwe desire to remove the threading mechanism or to change it to adifferent position, we first remove the cross pin 232 (Fig. 4), and thescrews 29. The support 21, the sleeve 22 and actuating mechanismtherefor, the shaft 23, the sleeves 62 and 66 and the collar 95 may thenbe removed as a unit. The sleeve 50, cap 50, and gears 52 and 53 maythen be drawn out of the tool head 15 to the left (Fig. 4) and thespindle 17 and die 16 may be removed to the right. The parts canthereafter be reassembled in a different operatin position or they maybe laid aside and t e usual fixed cutting tools may be substitutedtherefor.

Having thus described our invention it will be evident that changes andmodifications can be made therein by those skilled in the art withoutdeparting from the spirit and scope of our invention as set forth in theclaims, and we do not wish' to be other- Iwise limited to the detailsherein disclosed,

Whatwe do claim is:

1. In an automatic lathe, in combination, a threading die, driving meanseffective to rotate said die at each of two different speeds,controlling mechanism for said driving means, devices effective toadvance and retract said die axially, actuators for said devices, andmeans to support said devices, mechanism, and actuators in alinementwith either one of two successive operative posi; tions of the workspindle.

2. In an automatic lathe, in combination,

a threading die, means to rotate said die at each of two differentspeeds, a fixed frame member having guide-ways thereon, a removablesupport slidable on said ways, means to secure said support in fixedposition on said ways during the continued operation of the machine, andmechanism mounted on said support through which the thread-cuttingoperation may be controlled.

3. In an automatic lathe, in combination, a threading die, means torotate said die at each of two diflerent speeds, a fixed frame memberhaving two sets of guide-ways thereon, a support adapted to be mountedin fixed position on either one of said sets of ways, mechanism mountedon said support through which the thread cutting operation may becontrolled, and means to actuate said mechanism in either positionthereof.

4. In an automatic lathe, in combination, a threading die, means torotate said die at each of two different speeds, a fixed frame memberhaving two sets of guide-ways thereon, a support adapted to be mountedin fixed position on either one of said sets of ways, mechanism mountedon said support through which the operation of the threada threadingdie, driving means for rotating said die at each of two differentspeeds, de-

vices connected to move said die axially,

and a single actuating member effective to advance and retract said dieand to control the speed changes thereof.

6. In an automatic lathe, in combination, a threadin die, driving meanseffective to rotate the ie at each of two different speeds, a fixedframe member having guide-ways thereon, a support slidable on said ways,means to securesaid support in fixed posi named tionvon' said ways, arack slidable in said support, a gear pivoted on said support andmeshing with said rack, a segment gear on said support connected to turnsaid first ear, and actuating means movably mounte on said fixed framefor moving said segment gear in each direction.

'1 7. In an automatic lathe, in combination, a threading dle, a spindlethrough ,WlHCl'l said the is controlled, means to operate said spindleat each of two different speeds, a

fixed frame member having guide-ways slide said rack, a pawl effectiveto move said gear, rack and spindle in one direction, a second pawl.effective to move said parts in the opposite direction, and means tomove saidpawls.

8. In an automatic lathe, in combination, a threading die, a spindlethrough which said die is controlled, means to operate said spindle ateach of two different speeds, a fixed frame member having guide-waysthereon, a support slidable on said ways, means to secure said supportin fixed position on said ways, a rack sleeve slidable in said support,a segment gear connected to slide said sleeve, a: bar mounted forpositive longitudinal movement, a pawl on said bar effective to movesaid gear, sleeve and spindle in one direction, a second pawl on saidbar eflective to move said parts in the opposite direction, and thirdpawl on said bar efiective to change the speed of rotation of thethreading die.

9. In an automatic lathe, in combination, a threading die, a spindlethrough which said die is controlled, means to operate said spindle ateach of two different speeds, a

fixed frame member having guide-ways thereon, a support slidable on saidways,

means to secure said support in fixed position on said ways, a racksleeveslidable in said support, a segment gear connected to slide" saidsleeve, a bar mounted for positive longitudinal movement, a pawl on saidbar effective to move said gear and sleeve in one direction, asecond'pawl on said bar effective to move said gear and sleeve in theopposite direction, and a third pawl on said bar effective to change thespeed of rotation of the threading die, all of said pawls beingoperative during movement of said bar in one direction an beinginoperative during the return movement of said bar.

10. In an automatic lathe, a threading die, means to rotate said die inthe direction of rotation of the stock at either of two differentspeeds, mechanism for positioning and controlling said die, a barslidable parallel to the axis of the die, and a series of pawlsearriedby said bar and effective successively to advance said die, toincrease the speed of rotation thereof, and to thereafter return saiddie to initial position and restore the original speed of rotation allduringa single cc ntinued travel'of the .sliding bar in one diirection.

11. In an autonatic lathe, a threading die, means to rotates tld die inthe direction of rotation of the stock at either of two differentspeeds, mechanism for positioning and controllingszid die, a barslidable parallel to the axis-of the die, a series ofpawls carried bysaid bar and effective to advance said die, to increase the speed ofrotation thereof, and to thereafter return sa d die to initial positionand restore the original speed 7 of rotation all during a singlecontinued travel of the slicing bar in one direction, and cam-actuatedmeans for giving said bar an irregular reciprocating motion.

12. In a; threading attachment, a die, a spindle to which said die issecured, low and high speed gears loosely rotatable concentric with saidspindle, and pawl and ratchet mechanism by which either one of saidgears may be rendered effective to control said spindle and die, saidpawls being mounted on a sleeve loosely keyed to the spindle by atumbler effective to cause positive engagement of the low speed pawlwith its ratchet during the cutting ofthe thread.

13. In a threading attachment, a threading die, a spindle through whichthe die is controlled, a sleeve on said spindle, low and high speedgears rotatable outside of said sleeve, separate pawls slidabletransversely in said sleeve to cause engagement of said gears with saidsleeve, external adjustable mechanism for actuating the high speed pawl,and a device for forcing the low speed pawl into drivingpositionyieldingly when running idle and positively when cutting thethread.

14. In a threading attachment, a threading die, a spindle through whichthe rotation of the die is controlled, a sleeve on said spindle, a lowspeed gear rotatable concentric with said sleeve and having internalratchet teeth, a pawl slidable transversely in said sleeve, a springefi'ective to force said pawl lightly into engagement with said ratchetteeth, and a tumbler loosely confined in a r'ecessin said sleeve andengaging one end of said pawl, said spindle having a keyway thereinloosely fitting said tumbler and permitting limited angular movementbetween said spindl e and sleeve, said tumbler acting as a lever whenforced ahead by said spindle through engagement with the side of thekeyway aiid being effective to force said pawl positively outward" tooperatively engage said ratchet teeth.

15. In an autoi iatic lathe, in combination,

a threading die, driving means effective to rotate the die at each oftwo different speeds,

a fixed frame member, a support, means to secure said support in fixedposition on said frame, a rack slidable in said support, a gear pivotedon said support and meshing with said rack, a segment gear on'saidsupport connected to turn said first named gear, and actuating meansmovably mounted on said fixed frame for moving said segment gear in eachdirection. I

16. In an automatic lathe, in combination, a threading die, a spindlethrough which said die is controlled, means to operate said spindle ateachcof two different speeds, a

Copies 0! thin patent my be obtained for rack sleeve connected to saidspindle, a segment gear connected to slide said sleeve, a bar mountedfor positive longitudinal movement, a pawl on said bar effective to movesaid gear, sleeve and spindle in one direction, a second pawl on saidbar efi'ectiveto move said parts in the opposite direction, and a thirdpav'vl on said bar eflective to change the speed of rotation of thethreading die.

In testimony whereof we have hereunto set ourhands.

JAMES J. HOGAN. JOHN F. JUDD. LYMAN M. WAITE.

five cents each, by addressing the Commissioner of Patents, Washington,D 0.

